The above is a list of the first 100 words I’ve ‘mastered’ on the vocabulary.com site. Of course I knew some of them already, but I’ve also learned quite a few new words here along the way and it’d be incorrect to say that I haven’t also gotten a better grasp of some of the words with which I was already familiar. Here’s how it works. A few of the assessment questions so far have been in my opinion really poor (allowing for multiple correct answers, only one of which is accepted as correct), but in general this seems like an extremely useful site and the site does allow you to provide feedback if you think a question is poorly worded.

Do note that average vocabulary sizes are really rather small, all things considered: “Most adult native test-takers range from 20,000-35,000 words”. I think that you can probably progress rather rapidly with a tool like this, if you use it consistently. Note that the site doesn’t completely stop asking you questions about the words you’ve ‘mastered’; brush-up questions are added occasionally to aid retention. The starting point is as far as I can remember based on educational background, so if you’re a graduate student you shouldn’t worry that the site will start out by asking you if you know the word ‘house’ or ‘cat’. I’m pretty sure even walking dictionaries will find plenty of words along the way that they are unfamiliar with.

I’ll probably stop going on about the site now, but I really like it at this point and so I figured I should post at least a few posts about it before letting it go. It’s a very neat tool.

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ii. For the last two years I have been involved in a medical trial aimed at figuring out if a specific drug might be used to delay the development of retinopathy in diabetics. My participation in the trial ended this week. The trial was more or less a direct result of a smaller trial in which I also participated, which showed some promising initial results – here’s the relevant paper. The researcher conducting the trial I just participated in will publish a paper about it later on, and I’ll naturally blog that when it’s published. There has been talk about continuing the project (/…that is, starting a new project) for the participants who got the active drug – half of the people in this trial got placebo – in order to increase the follow-up period. If I got the active drug (whether or not I did is not clear at this point, but I’ll be told relatively soon) I’ll probably participate in the new trial as well. No, the person who’s going to analyze the data will not be told whether or not I got the active drug – I asked about this part, but the study design is such that the double blind aspect is not compromised; the researcher who’ll figure out whether or not I got the active drug is not involved in the data analysis at all.

Medical trials often have trouble finding participants and selection into such trials is far from random. If you live in Denmark, you should check out this site. I assume similar resources exist in other countries…

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A couple more 60 symbols videos below. I’ve now watched most of the videos they’ve posted, and I really like this stuff:

“He was a very strange man. And yet he’s absolutely wonderful!” – I could easily have said something similar about him. I’d much, much rather spend time with someone like that than with a ‘normal’ (boring) person. (Here’s a related link. Also, this.)

“The aim of the current study was to examine the relationship between individual differences in anxiety and the social judgements of trustworthiness and approachability. We assessed levels of state and trait anxiety in eighty-two participants who rated the trustworthiness and approachability of a series of unexpressive faces. Higher levels of trait anxiety (controlling for age, sex and state anxiety) were associated with the judgement of faces as less trustworthy. In contrast, there was no significant association between trait anxiety and judgements of approachability. These findings indicate that trait anxiety is a significant predictor of trustworthiness evaluations and illustrate the importance of considering the role of individual differences in the evaluation of trustworthiness. We propose that trait anxiety may be an important variable to control for in future studies assessing the cognitive and neural mechanisms underlying trustworthiness. This is likely to be particularly important for studies involving clinical populations who often experience atypical levels of anxiety.”

“The Cretaceous–Paleogene (K-Pg) boundary is marked by a major mass extinction, yet this event is thought to have had little effect on the diversity of lizards and snakes (Squamata). A revision of fossil squamates from the Maastrichtian and Paleocene of North America shows that lizards and snakes suffered a devastating mass extinction coinciding with the Chicxulub asteroid impact. Species-level extinction was 83%, and the K-Pg event resulted in the elimination of many lizard groups and a dramatic decrease in morphological disparity. Survival was associated with small body size and perhaps large geographic range. The recovery was prolonged; diversity did not approach Cretaceous levels until 10 My after the extinction, and resulted in a dramatic change in faunal composition. The squamate fossil record shows that the end-Cretaceous mass extinction was far more severe than previously believed, and underscores the role played by mass extinctions in driving diversification.”

A little more:

“Survival at the K-Pg boundary is highly nonrandom. Small size has been identified as a determinant of survival (36), yet size selectivity is evident even among the squamates. The most striking pattern is the extinction of all large lizards and snakes. […] The largest known early Paleocene lizard is Provaranosaurus acutus. Comparisons with varanids suggest an SVL [snout-vent length, US] of 305 mm and a mass of 415 g (Dataset S1), compared with an estimated SVL of 850 mm and mass of 6 kg for the largest Maastrichtian lizard, Palaeosaniwa. The largest early Paleocene snake is Helagras prisciformis, with an estimated SVL >950 mm and a mass >520 g, compared with >1,700 mm and 2.9 kg for the largest Maastrichtian snake, Cerberophis. […]

Size selectivity may help explain why nonavian dinosaurs became extinct, suggesting that it was nonavian dinosaurs’ failure to evolve a diverse fauna of small-bodied species, rather than a decrease in the diversity of large-bodied forms, that ultimately sealed their fate. A number of small, nonavian dinosaurs are now known from the Late Cretaceous, including alvarezsaurids (37) and microraptorine dromaeosaurids (38), and taphonomic biases almost certainly obscure the true diversity of small dinosaurs (38, 39). However, the fact remains that during the late Maastrichtian, small dinosaurs were vastly outnumbered by other small vertebrates, including a minimum of 30 squamates, 18 birds (15), and 50 mammal species (40). Strikingly, birds—the only dinosaurs to survive— were the only dinosaurs with a high diversity of smallbodied (<5 kg) forms (15). In this context, a discussion of a decline in large dinosaur diversity in the Maastrichtian (9) is perhaps beside the point. A high diversity of large herbivores and carnivores in the latest Maastrichtian would have been unlikely to change the fate of the nonavian dinosaurs, because no animals occupying these niches survived. Instead, the rarity of small dinosaurs—resulting perhaps from being outcompeted by squamates and mammals for these niches —led to their downfall. […]

Extinction at the K-Pg boundary was followed by recovery in the Paleocene and Eocene. A number of new lizard lineages occur in the basal Paleocene, notably the stem varanoid Provaranosaurus, xantusiids, and amphisbaenians (27). These may represent opportunistic invaders that colonized the area in the aftermath to exploit niches left vacant by the extinction, as seen among mammals (10, 44). Despite this, early Paleocene diversity is considerably lower than late Maastrichtian diversity (Fig. 3). Subsequently, ecological release provided by the extinction allowed the survivors to stage an adaptive radiation, paralleling the adaptive radiations staged by mammals (6, 45, 46), birds (46, 47), and fish (48). The community that emerges in the early Eocene is dominated by groups that are either minor components of the Cretaceous fauna or unknown from the Cretaceous […] diversity does not approach Cretaceous levels until the early Eocene, 10 My later […] Unlike mammals, […] squamates appear to have simply reoccupied the niches they occupied before the extinction. This reoccupation of niches was […] delayed; by the middle Paleocene, lizards had yet to recover the range of body sizes and morphotypes found in the Maastrichtian (Fig. 5).”

About me/this blog

This blog is mainly a site where I keep track of and share some of the stuff I read and learn. Only a small subset of the posts on this blog deal with economics – I have diverse interests, and as the category cloud in the sidebar below illustrates this blog contains posts about all kinds of stuff: Mathematics, physics, statistics, geology, geography, health care and medicine, psychology, evolutionary biology, genetics, history, anthropology, archaeology, chess, …

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"Happiness and its anticipation are […] proximate mechanisms that lead us to perform and repeat acts that in the environments of history, at least, would have led to greater reproductive success." (Richard D. Alexander)